Hi, i checked my site that has been working fine for months today, and I noticed that the quickslider on the homepage stopped working and also clickdesk live chat. This happened without me making any changes.

Its not possible for something to just stop working if it was working, without changes being made. This could be an update to Wordpress, plugin, scripts or even your server. Therefore, I recommend you disable all active plugins and see if the QuickSlider starts working again, then we know its related to a plugin.